The present invention relates generally to a technical filed of a digital image shooting device such as a digital camera, and more particularly to a digital image shooting device capable of photographing (outputting) a high-quality image of which aberrations are corrected even in a case of incorporating a comparatively low-price lens which performance is not so good.
A digital camera, which had initially a small number of pixels and of which representation was in monochrome, has therefore been limited its use to a special application. With a remarkable decrease in costs for the electronic parts of CCD sensors, etc., however, a color representation becomes possible easily, and the application of image data processing expands with a spread of a personal computer. Under such circumstances, the digital camera sharply decreases in price and seems to be popularized.
Recently, a high quality digital camera of which pixel number exceeds 1,000,000 have been commercialized one after another, and also with regard to a memory for storing (recording) the image, there is a tendency of the digital camera to shift from a type of being built in the body of it to a type of using a removable storage medium having a larger capacity.
In the latter type of the digital camera using the removable storage medium, a process of taking the recorded image data into a personal computer becomes highly simple.
As explained above, an enhancement of the image quality in the digital camera is largely influenced by, in addition to an increase in the number of recordable pixels, a performance improvement of an image forming lens, and an improvement of an image processing technology of the photographed image data.
For instance, some of the digital cameras (DS-300 made by Fuji Photo Film Co.,Ltd.) use a 3-powered zoom lens as an image forming lens, of which a lens configuration is based on 3 lens units containing 9 lens elements, and this type of the digital camera becomes substantially equal to a compact camera in terms of the image quality.
However, by using the high-accuracy and high-performance lens, the digital camera which can output the high-quality image can be realized and, while on the other hand, it might be a factor for raising the costs of the digital camera.
conversely, by using the comparatively low-price lens, it is possible to decrease the costs of the digital camera. However it can not be denied that the low-price lens is inferior in performance so that for example, there might occur a chromatic aberration of magnification, a distortion aberration and a decrease in marginal lumination, and quality of the image falls down such that a distortion and a density gradient occur with the outputted image.